The respiratory system

Learning goals We are learning to identify the parts and function of the respiratory system. We are learning to connect breathing and gas exchange. We are learning to identify the training effects on the respiratory system.

Let’s begin! Respiration

2 Major respiratory system zones CONDUCTIVE ZONE (“the respiration ‘tree’”) PURPOSE: filters and brings air to the lungs CONSISTS OF: nose/mouth - containing cilia (filtration) trachea - containing mucous membranes (humidification) & many capillaries (bring air to body temp.) right & left bronchi (bronchus - sing.) - branch off trachea into lungs bronchioles - branch off the bronchi

RESPIRATORY ZONE PURPOSE: where gas exchange occurs CONSISTS OF: approx. 300 million ALVEOLI that are only 1 cell thick (clustered together like grapes to form ALVEOLAR SACS) Why multiple sacs? to increase surface area each sac is surrounded by a web of capillaries (also only 1 cell thick) Why are both the alveoli & capillaries only 1 cell thick? to allow for easy diffusion

Watch this! Respiratory System

LUNG FUNCTION (RESPIRATION)

STEP 1: AIR MOVES THROUGH THE CONDUCTIVE ZONE diaphragm contracts downward lungs expand to fill the empty space air pressure inside the lungs decreases (b/c there’s more space for it) air is forced into the lungs since there’s more pressure in the atmosphere than in the lungs as diaphragm relaxes, it forces lungs to get smaller again thus, there is more pressure inside the lungs than in the atmosphere air is forced out

STEP #2: GAS EXCHANGE OCCURS IN THE RESPIRATORY ZONE when we breathe in, PARTIAL PRESSURE OF O2 is higher in the alveoli than in the capillaries (in a mixture of gases, the PP is the pressure each gas would exert if it was the only gas in the same sized container) therefore, it wants to move from an area of high pressure (in alveoli) to an area of low pressure (in the capillaries) = diffusion (again!) likewise, CO2 wants to move from an area of high pressure (in capillaries) to an area of low pressure (in the alveoli)

Watch! Gas Exchange

training

RESPIRATORY TRAINING unlike cardiovascular system which adapts to aerobic training very quickly, respiratory system adapts very little only significant change is in TIDAL VOLUME of lungs, due to increases in strength & endurance of respiratory muscles (e.g. diaphragm) tidal volume (Vt): the volume of air in each breath

VO2 MAX maximal amount of O2 that can be taken in and used for the metabolic production of ATP during exercise an excellent measure of aerobic (cardiovascular) fitness measured in mL/kg/min limited by all 3 systems (C-V, Respiratory, Metobolic/Energy), but most likely limited by the C-V system Lance

Factors contributing to higher oxygen consumption include: Amount of oxygen carried in the blood (haemoglobin) Amount of blood the heart can pump per minute (Q impacted by SV) Amount of oxygen taken up by the cells as the blood flows through the tissue. Efficient blood flow (efficient venous return, capillary growth) Consequently, C-V function can be used to estimate VO2Max

People vary in their VO2 max due to: Heredity Training Sex: Males have a 15%-30% higher VO2max. Because of body composition (fat vs muscle, and height) and haemoglobin content. Age: this peaks at 18 -25 years of age.

Learning goals We are learning to identify the parts and function of the respiratory system. We are learning to connect breathing and gas exchange. We are learning to identify the training effects on the respiratory system.